JP2008136099A - Tracking imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tracking imaging apparatus in which wiring of the fixed side and the movable side of a pan or tilt mechanism is omitted, which is not influenced by photographic environment, with a wide imaging area and capable of tracking a target object freely and in a wide range. <P>SOLUTION: (1) A rotary transformer is provided between the fixed side and the movable side of a pan or tilt rotation mechanism. (2) An encoder and a decoder for restricting bands are provided in order to pass the rotary transformer. (3) A tracking search means for rotating the pan or tilt rotation mechanism at fixed speed is provided. (4) One of the pan or tilt rotation mechanism is provided with an infinite rotation means and the other is provided with a finite rotation means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an imaging apparatus and tracking means for tracking a tracking target detected by image processing by changing an imaging direction so as to be at a predetermined position, for example, the center of a screen.

  2. Description of the Related Art Conventionally, an imaging system has been proposed in which an object of interest is detected by an imaging device using a substantially orthogonal pan and tilt mechanism, and the imaging direction is controlled and tracked so that the position is at the center of the screen or a specific location. . In such an imaging tracking system, the pan and tilt mechanism is controlled so that the amount of deviation between the position of the subject to be tracked and the predetermined imaging area is small. FIG. 15 is a flowchart for explaining this process. S51 is the start of processing, which corresponds to a power ON to the apparatus, a user command, or the like. S52 is an initialization step such as moving the pan or tilt mechanism to the center of rotation, for example. S53 is a tracking target detection step for detecting a tracking target from the characteristics of the subject of interest. S54 is a control amount calculation step for calculating a deviation between the tracking target position and the imaging direction, that is, the pan and tilt directions, and calculating a control signal corresponding to the pan and tilt mechanism. S55 is a pan and tilt mechanism driving step that operates in response to a control signal from S54, and S54 and S55 often form a feedback control system. By repeating the steps S53 to S55, it is possible to perform tracking imaging of the subject.

Since either the pan mechanism or the tilt mechanism is rotationally driven, the mechanism is divided into a fixed side and a rotational side. In addition, transmission of signals and electric power is required between the fixed side and the rotating side. Usually, transmission of signals and electric power has been performed by lead wires, flexible boards, and the like. Further, a patent reference discloses a method using a rotary transformer as a method not using a lead wire or a flexible substrate. In this reference, a one-dimensional imaging device and an optical system are rotationally scanned to image a place such as the inside of a tube. A rotary transformer is used for this signal transmission.
JP-A-11-122526

  In the conventional example using the above lead wire or flexible substrate, since the lead wire or the flexible substrate is wired on the fixed side and the rotation side of the rotation mechanism of the pan or tilt mechanism, the wiring is deformed or excessively stressed. . For this reason, it is necessary to generate a torque for overcoming the resistance torque of the wiring, and there has been a tendency to be large and expensive in order to increase the rigidity of the drive mechanism. Further, if the rotation angle is increased, the wiring is disconnected and the rotation angle is limited.

  Usually, conductive members for wiring such as lead wires and flexible substrates are made of metal such as copper. When stress is repeatedly applied to the metal, disconnection occurs due to metal fatigue.

  Further, in the conventional example disclosed in Patent Document 1, since the inside of the tube is rotationally scanned by a one-dimensional sensor, it can be used only in a very limited imaging environment.

  Accordingly, an object of the present invention is to provide an imaging apparatus having a wide imaging range that is not affected by the imaging environment by omitting the fixed and movable wirings of the pan or tilt mechanism. Furthermore, a tracking imaging device capable of tracking a target freely and in a wide range is provided.

  The following are the problems to be solved.

  (1) To provide an infinite rotation means capable of controlling rotation of pan or tilt unlimitedly by 360 ° or more.

  (2) The controllability deterioration due to the rotation angle position due to wiring is eliminated.

  (3) Eliminates torsional load torque due to wiring.

  (4) Eliminate the disconnection due to metal fatigue of the wiring and extend the life of the device.

  In order to achieve the object of the present invention, for example, a tracking imaging apparatus of the present invention comprises the following arrangement.

  An imaging unit configured of a predetermined optical system for acquiring an image, a tracking target detection unit for detecting a tracking target from an imaging signal of the imaging unit, and for tracking the tracking target by mechanically changing an imaging direction A pan control unit that rotates in a horizontal direction, a tilt control unit that rotates in a vertical direction, and a tracking imaging apparatus that controls the amount of deviation between the tracking target and the imaging direction to be small, the rotation mechanism of the pan control unit or the tilt control unit A rotary transformer is provided between the rotation side and the fixed side, and pan or tilt drive control and camera control means are provided via the rotary transformer.

  It comprises signal conversion means for removing the direct current component or low frequency component and supplying it to the rotary transformer, and inverse conversion means for returning the signal via the rotary transformer to the signal before conversion.

  The apparatus further includes means for superimposing any one of a signal of the pan control means, a signal of the tilt control means, a signal of the camera control means, an imaging signal of the imaging means, and an AC power supply.

  One of the rotation side or the fixed side of the pan or tilt means is provided with an AC power source, and the other is provided with a rectifying means for converting AC power into DC power, and the AC power is provided with means for supplying the AC power via a rotary transformer.

  An imaging unit configured of a predetermined optical system for acquiring an image, a tracking target detection unit for detecting a tracking target from an imaging signal of the imaging unit, and for tracking the tracking target by mechanically changing an imaging direction In a panning control unit that rotates in the horizontal direction and a tilt control unit that rotates in the vertical direction, and a tracking imaging device that controls the amount of deviation between the tracking target and the imaging direction to be small, the tracking target is detected when the tracking target is not detected. Tracking search means for rotating the pan or tilt at a predetermined speed is provided.

  An infinite rotation means is provided for one or both of pan and tilt.

  When the tracking search means is operating, means for changing the speed only in a predetermined section is provided.

  Means is provided for increasing the rotation speed of the pan or tilt only in the section where the shooting is blocked by the support structure on the one of the pan and tilt. An imaging unit configured of a predetermined optical system for acquiring an image, a tracking target detection unit for detecting a tracking target from an imaging signal of the imaging unit, and for tracking the tracking target by mechanically changing an imaging direction Pan control means that rotates in the horizontal direction, tilt control means that rotates in the vertical direction, and a tracking imaging device that controls the amount of deviation between the tracking target and the imaging direction to be small. Infinite angle rotation means, and finite rotation means on the other side.

  The finite rotation means includes a movable mirror rotation control means.

  The present invention has the following effects.

  (1) The pan or tilt rotates indefinitely by 360 ° or more, and there is no restriction of control by the rotational angle position.

  (2) Since there is no wiring, durability is improved.

  (3) Since no load torque is generated by wiring, the rotational drive mechanism system can be made small and inexpensive.

  Hereinafter, the present invention will be described in detail according to preferred embodiments with reference to the accompanying drawings.

  The configuration and characteristics of the present invention in which a rotary transformer is provided between the rotation side and the fixed side on either or both of the pan and tilt rotation mechanisms will be described. There are two types of mechanism of the imaging apparatus according to the present invention, in which the pan mechanism is mounted on the tilt drive mechanism opposite to the tilt drive mechanism mounted on the pan drive mechanism. In general, the former pan drive mechanism has many tilt mechanisms, and the following description will be made in this form. Note that the essence of the present invention does not change even in the case where the pan mechanism is mounted on the latter tilt mechanism.

(First embodiment)
In the first embodiment, both the pan and tilt rotation mechanisms are provided with a rotary transformer between the fixed side and the rotation side to transfer signals or power, and the pan or tilt can be rotated indefinitely by 360 ° or more. Examples will be described with reference to FIGS. 1 to 7.

  1 to 5 are views showing the mechanism of the present invention. FIG. 1 is a front view, FIG. 2 is a plan view, FIG. 3 is a right side view, FIG. 4 is an upper left front perspective view, and FIG. 5 is a lower left rear perspective view as viewed from the subject side of the tracking imaging device. FIG. 6 is a sectional view of the rotary transformer, and FIG. 7 is a block diagram showing the overall configuration of the first embodiment.

  The reference numerals shown in FIGS. 1 to 5 for explaining the mechanism will be described. Reference numeral 1 denotes a camera module for capturing an image of the imaging apparatus. The optical system of the camera module is composed of a plurality of lenses, and the exit pupil position is desirably arranged on or near the pan and tilt rotation axes described later. Reference numeral 2 denotes a main frame for fixing the imaging mechanism unit, which is fixed to a predetermined apparatus or facility. It can also be placed on the ceiling or wall of buildings such as offices and homes. In the drawings of the present invention, the fixing device and facility are omitted. 3 is a pan rotation axis for rotating the tilt mechanism in the pan direction to 360 ° or more without restriction. Reference numeral 4 denotes a motor for rotationally driving the pan, and includes a stationary side 4S and a rotational side 4R. The motor 4 is a brushless DC motor, the stationary side 4S is constituted by a coil, and the rotation side 4R is constituted by a magnet. It should be noted that there is no problem in the rotation driving of the pan even in other configurations such as using a reduction gear or in a system other than the brushless DC motor. 5 is a rotary transformer, 5R is a rotation side, and 5S is a fixed side. Reference numeral 6 denotes a tilt frame for holding a tilt mechanism that rotates in the pan direction. Reference numerals 7 and 8 denote tilt rotation axes for rotating the camera module in the tilt direction to 360 ° or more without restriction. Reference numeral 9 denotes a camera frame for supporting the camera module 1, which is rotationally driven in the tilt direction via the camera frame. Reference numeral 10 denotes a motor, which is composed of a fixed side 10S and a rotating side 10R, similar to the motor 4. 11 is a rotary transformer similar to 5 and is composed of a fixed side 11S and a rotating side 11R. Thus, by omitting the wiring using the rotary transformer, the pan motor 5 and the tilt motor 10 can be rotated indefinitely by 360 ° or more. For example, in the conventional example in which the angle of the pan is about 270 °, about 90 ° is a blind spot for photographing, which is a restriction on installation.

  FIG. 6 is a sectional view of the rotary transformer 11 for explaining the rotary transformer. As shown in FIG. 6, the rotary transformer is composed of two members, a fixed side 11S and a rotating side 11R. 11R-CR and 11S-CR are cores made of magnetic material such as ferrite, and 11R-a, 11R-b, 11R-c, 11S-a, 11S-b, and 11S-c are grooves provided in the respective cores. It is a wound coil. The coil is pulled out by providing a hole (not shown) on the bottom surface of the core groove. The 11R-CR fixed side 11S and the rotation side 11R have substantially the same shape, and a gap of several tens of μm is provided. Although there is no opportunity coupling due to this gap, 11S-a and 11R-a, 11S-b and 11R-b, and 11S-c and 11R-c are magnetically coupled as a transformer. This combination is called a channel. If the number of windings is changed as in a normal transformer, a step-up ratio corresponding to that is obtained.

  The block diagram of the overall configuration of FIG. 7 will be described in detail. In the figure, reference numeral 21 denotes a tracking target detection unit for extracting a tracking target such as a human face from an image and detecting its position. Many methods for extracting tracking targets have been proposed and implemented, such as those using template matching. A control amount calculation unit 22 compares the detection value of the tracking target detection unit 21 with the rotation angle of pan or tilt, and calculates an appropriate control amount. The control calculation calculation unit includes a pan calculation unit 23 that calculates a control amount of the pan rotation angle, a tilt calculation unit 24, and an imaging control unit 25 that controls the camera module 1. Reference numeral 26 denotes a pan rotation drive unit according to the calculation result of the pan calculation unit 23 and includes the rotation mechanism and motor described above. Reference numerals 27 and 28 denote encoders for passing signals through the rotary transformer. The rotary transformer is electromagnetically an AC circuit, and a method of removing a direct current or a low frequency band is used for passing the rotary transformer. A typical signal is converted from an 8-bit signal to a 10-bit signal, and the spectrum of the signal is limited by a predetermined table. Reference numeral 29 denotes a decoder, which performs the reverse of the above-described conversion, for example, conversion from 8 bits to 10 bits, and returns to the normal data format. In order to pass through the rotary transformer in this way, an encoder and a decoder are generally required. Reference numeral 30 denotes an AC power source, which supplies power to a drive unit and a processing unit mounted on the pan mechanism via the rotary transformer 5. The frequency of the AC power source is set to a frequency that reduces crosstalk with respect to other signals. The rotary transformer has channels for each signal and electric power. In the case of the rotary transformer 5, there are four channels from 5a to 5d. As shown in the figure, CHa is assigned for power, CHb is assigned for tilt rotation control signal, CHc is assigned for camera module control signal, and CHd is assigned for camera module video signal. Reference numeral 31 denotes a tilt rotation unit that is mechanically mounted on the pan rotation unit. Reference numeral 32 denotes a rectifying unit that converts electric power from the AC power source 30 into a DC power source for driving the tilt rotating unit, and covers a circuit power supply on the rotary side of the rotary transformer 5. A tilt rotation driving unit 33 is controlled according to the result of the tilt calculation unit. Reference numerals 34 and 35 denote amplifiers for performing signal amplification and the like for sending to the rotary transformer 11 as necessary. In some cases, amplifiers 34 and 35 are not provided. 11 a and 11 b are channels provided in the rotary transformer 11. 11a is for the video signal of the camera module 1, and 11b is for controlling the camera module. The camera module 1 includes a video signal unit 1a that converts a subject into a video signal and a control unit 1b that controls the aperture and focus of the camera module.

  Further, the number of channels of the rotary transformer can be reduced by superimposing the tilt calculation unit and the imaging signal described above or passing the rotary signal in time series.

  The flow of pan control, tilt control, camera control, and video signal will be described as operations of the first embodiment with reference to FIG. In the pan control, the tracking target and position are detected by the tracking target detection unit 21. In accordance with the tracking position, the pan calculation unit 23 in the control amount calculation unit 22 calculates a control amount for driving the pan mechanism, sends a signal to the pan rotation drive unit 26, and the pan drive is controlled. In the tilt control, the control amount is calculated by the tilt calculation unit as in the case of pan. After the calculation result is converted by the encoder 27, a signal is sent to the tilt rotation drive unit 33 via the CHb of the rotary transformer 5 and controlled. Controls such as the aperture and zoom of the camera are calculated by the imaging control unit 25, and the signal converted by the encoder 28 is sent to the amplifier 34 of the tilt rotation unit 31 via the CHc of the rotary transformer 5. The signal amplified by the amplifier 34 is transmitted to the control unit 1b of the camera 1 via the CHb of the rotary transformer 11, and the camera 1 is controlled. The video signal picked up by the camera 1 is converted by the video signal unit 1 a in the same manner as the encoder 27 and sent to the amplifier 35 via the CHa of the rotary transformer 11. The amplified signal is reversely converted by the decoder 29 via the CHd of the rotary transformer 5 and the video signal is supplied to the tracking target detection unit 21.

  As described above, by providing a rotary transformer between the rotating side and the fixed side of the mechanism to transmit a signal or electric power, the wiring on the fixed side and the rotating side of the mechanism can be omitted. As a result, the rotation angle of the rotation mechanism can be restricted, that is, unlimited rotation can be performed. There is no wiring load and the size of the device is reduced, and at the same time, there is no failure or shortened life due to disconnection.

(Second embodiment)
For example, in the form described in the first embodiment, if the top and bottom of the state shown in FIG. 1 is reversed and installed on the ceiling of a predetermined room, most of the room can be seen. It is suitable mainly for monitoring applications. In the second embodiment, the tracking target extraction and tracking operation utilizing the feature of the present invention that can rotate 360 ° or more will be described.

  FIG. 8 is a flowchart for explaining the operation of the second embodiment. In the figure, S1 is an operation start step, which corresponds to power-on or reset operation. S2 is a tracking target extraction step for detecting a tracking target from an image projected by the camera module 1. The tracking target to be extracted is different, for example, a specific person for watching purposes and a suspicious person for monitoring purposes. S3 is a tracking target extraction determination step for determining whether or not a tracking target is extracted. If it is determined that it exists, the process branches to S4, and if it is determined that it does not exist, the process branches to S6. S4 is a tracking operation step for tracking the extracted target. The tracking operation is to photograph the tracking target substantially at the center of the screen by driving the pan or tilt mechanism while detecting the tracking target and its position. S5 is a tracking target detection determination step for detecting whether the tracking target is present or missing. A loop is formed by step 4 in which it is determined in S5 that there is a tracking target. The process branches to S6 where it is determined that there is no tracking target in S5.

  S6 is a camera rotation step for rotating the camera module in both pan and tilt directions or one direction, and the process returns to step S2. By repeating the above steps, it is possible to perform tracking shooting of the entire predetermined area without being influenced by the angle of view and the rotation angle limit of the camera module.

  In the configuration where the two axes rotate like the mechanism of the first embodiment, one of them is a supporting member, so it is a blind spot for shooting. In the first embodiment, a shooting blind spot occurs on the tilt side. Shooting during this blind spot is meaningless. FIG. 9 is a diagram showing the rotation control speed of the tilt of the camera rotation step 6 corresponding to this blind spot photographing. The vertical axis represents the target rotational speed of tilt, and the horizontal axis represents the rotational position angle of tilt. In this drawing, the horizontal is 0 °, and the range between α1 and α2 is a blind spot photographing section of tilt. Thus, by increasing the speed of the blind spot imaging section, the blind spot imaging time can be shortened and a large effective imaging time can be obtained.

(Third embodiment)
In the first embodiment, a mode in which both pan and tilt rotate 360 ° or more has been described. When installed on the ceiling or wall, the imaging solid angle is often sufficient to be a hemisphere without having to cover the entire globe. In this embodiment, a device capable of photographing a hemisphere is proposed.

  10 to 14 show the mechanism of the present invention. 10 is a front view, FIG. 11 is a plan view, FIG. 12 is a left side view, FIG. 13 is an upper left front perspective view, and FIG. 14 is a lower left rear perspective view as viewed from the subject side of the tracking imaging device.

  Reference numerals shown in FIGS. 10 to 14 for explaining the mechanism will be described. In addition, the same code | symbol is used about the same thing as 1st Example, and description is omitted. 41 is the same as that of the camera module 11, but the mounting direction is different as shown. 42 is a tilt frame similar to the tilt frame 6 and has a different shape. Reference numeral 43 denotes a reflection mirror provided instead of rotating the camera module in the tilt direction. Twice the rotation angle of the reflection mirror 43 is the tilt angle. Here, the reflection mirror rotation angle will be described as a specific example. In order to cover the shooting solid angle more than a hemisphere, the pan needs to be 360 ° or more and the tilt needs to be 90 ° or more. If the angle of view of the camera module is 40 °, a tilt of 50 ° is required. If a reflecting mirror is used, it can be said that it is realistic at a rotation angle of about 25 °, which is half of this. Reference numeral 44 denotes a mirror rotation shaft that rotatably supports the rotary mirror 43, and also supports the arm 45 and the rotation angle sensor. Reference numeral 47 denotes a magnet, and reference numeral 48 denotes a coil. When a current is passed through the coil 48, the rotational force is transmitted to the mirror rotation shaft 44 via the arm 45. A predetermined tilt angle can be controlled by controlling the current or voltage of the coil 48 while referring to the rotation angle of the sensor 46.

  By using a rotating mirror in this way, an imaging solid angle of about a hemisphere can be easily configured. The gap of the rotary transformer needs to be assembled with high accuracy of about several tens of μm, and the encoder and decoder circuits are also required. In this way, if the rotating mirror is configured to rotate about several tens of degrees, the rotary transformer can also be configured as one set and inexpensively.

Front view of the mechanism of the first embodiment Mechanism plan view of the first embodiment Right side view of the mechanism of the first embodiment First embodiment mechanism upper left front perspective view Lower left rear perspective view of the mechanism of the first embodiment Cross section of rotary transformer Overall configuration block diagram of the first embodiment Operation flowchart of the second embodiment Tilt rotation speed target diagram of the second embodiment Mechanism front view of the third embodiment Mechanism plan view of the third embodiment Mechanism right side view of the third embodiment Upper left front perspective view of mechanism of third embodiment Lower left rear perspective view of mechanism of third embodiment Conventional flowchart

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Camera module 2 Main frame 3 Pan rotation axis 4 Pan motor 5 Rotary transformer 6 Tilt frame 7, 8 Tilt rotation axis 9 Camera frame 10 Motor 11 Rotary transformer S1 Operation start step S2 Tracking target extraction step S3 Tracking target extraction determination step S4 Tracking operation step S5 Tracking target detection determination step S6 Camera rotation step 21 Tracking target detection unit 22 Control amount calculation unit 23 Pan calculation unit 24 Tilt calculation unit 25 Imaging control unit 26 Pan rotation drive unit 27, 28 Encoder 29 Decoder 30 AC power source Reference Signs List 31 tilt rotation unit 32 rectification unit 33 tilt rotation drive unit 34, 35 amplifier 41 camera module 42 tilt frame 43 reflection mirror 44 mirror rotation shaft 45 arm 46 rotation angle sensor 47 magnet 4 Coil S51 mechanism driving step of starting S52 initialization step S53 tracking target detecting step S54 control amount calculating step S55 pan and tilt of the process

Claims (10)

An imaging means configured to obtain an image configured by a predetermined optical system;
Tracking target detection means for detecting a tracking target from the imaging signal of the imaging means;
Pan control means for rotating in the horizontal direction for tracking the tracking target by mechanically changing the imaging direction, and tilt control means for rotating in the vertical direction;
In the tracking imaging device that controls the deviation amount between the tracking target and the imaging direction to be small,
Tracking imaging characterized by comprising a rotary transformer between the rotation side and the fixed side of the rotation mechanism of the pan control means or tilt control means, and performing pan or tilt drive control and camera control via the rotary transformer. apparatus. The apparatus of claim 1.
A tracking imaging apparatus comprising signal conversion means for supplying a signal from which a direct current component or low frequency component has been removed to a rotary transformer, and inverse conversion means for returning the signal via the rotary transformer to a signal before conversion. The apparatus of claim 2.
A tracking imaging apparatus, further comprising means for superimposing any one of a signal from a pan control means, a signal from a tilt control means, a signal from a camera control means, an imaging signal from an imaging means, and an AC power supply. The apparatus of claim 1.
An AC power source is provided on one of the rotating side and the fixed side of the pan or tilt means, and a rectifying means for converting AC power into DC power is provided on the other side, and the AC power is supplied via a rotary transformer. Shooting device. An imaging means configured to obtain an image configured by a predetermined optical system;
Tracking target detection means for detecting a tracking target from the imaging signal of the imaging means;
Pan control means for rotating in the horizontal direction for tracking the tracking target by mechanically changing the imaging direction, and tilt control means for rotating in the vertical direction;
In the tracking imaging device that controls the deviation amount between the tracking target and the imaging direction to be small,
2. The tracking imaging apparatus according to claim 1, further comprising tracking search means for rotating one or both of pan and tilt at a predetermined speed in order to detect the tracking target when no tracking target is detected. The apparatus of claim 5.
6. The tracking photographing apparatus according to claim 5, wherein infinite rotation means is provided for one or both of pan and tilt. The apparatus of claim 5.
A tracking imaging apparatus characterized by changing the speed only in a predetermined section when the tracking search means is operating. The apparatus of claim 7.
A tracking photographing apparatus characterized in that the rotational speed of panning or tilting is increased only in a section where photographing is shielded by a support structure on one of panning and tilting. An imaging means configured to obtain an image configured by a predetermined optical system;
Tracking target detection means for detecting a tracking target from the imaging signal of the imaging means;
Pan control means for rotating in the horizontal direction for tracking the tracking target by mechanically changing the imaging direction, and tilt control means for rotating in the vertical direction;
In the tracking imaging device that controls the deviation amount between the tracking target and the imaging direction to be small,
A tracking imaging apparatus characterized in that an infinite angle rotation means is provided on one of the pan or tilt photographing direction changing means and a finite rotation means is provided on the other. The apparatus of claim 9.
A tracking imaging apparatus using a movable mirror as a finite rotation means.

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